Genetic diversity and haplotype analyses of Anopheles stephensi Liston 1901 using ITS2 and COI markers

Anopheles stephensi a prominent vector in urban India and an emerging vector in African countries, significantly contributes to malaria transmission. This study explores the genetic diversity, haplotype network, and phylogenetic analyses based on the Internal Transcribe Spacer 2 (ITS2) and Cytochrome Oxidase c subunit I (COI) publicly available GenBank repository. A total of 73 ITS2 and 64 COI sequences were used for analysis, out of 140 and 111 retrieved sequences, respectively. The phylogenetic analysis of ITS2 sequences through Bayesian approaches reveals two distinct clades, whereas, COI sequences reveal six distinct clades with posterior probability (pp) 100%. Haplotype network analysis for ITS2 shows four haplotypes with one shared haplotype and three private haplotypes and COI shows nine haplotypes with two shared haplotypes and seven private haplotypes. The genetic heterogeneity based on 73 ITS2 and 64 COI sequences, reveals low haplotype diversity (Hd) values of 0.532 and 0.435, respectively. Tajima's D value is found to be -1.53298 (P > 0.10) for COI sequences, suggesting an excess of rare mutations, while 4.91417 (P < 0.001), value for ITS2, indicates fewer rare mutations, implying balancing selection. These findings enhance the genetic diversity and population structure of Anopheles stephensi, which has potential implications for vector control strategies.